Wetlands like Wax Lake Delta along Louisiana’s coast store massive amounts of carbon, which can contribute to CO2 emissions when lost. (Photo Credit: Elise Plunk/ Louisiana Illuminator
ST. MARY PARISH – Louisiana’s wetlands are one of the planet’s most vital carbon storage centers, but destroying these reservoirs can accelerate harmful emissions that intensify global warming, according to experts.
The Trump administration is fast-tracking energy projects, such as the Blue Marlin Offshore Port crude oil pipeline near Lake Charles that could destroy about 234 acres of wetlands, according to the Environmental Integrity Project. New research finds the stakes for Louisiana’s coast are even higher than previously thought.
On a sunny afternoon in early February, rainbows of microorganisms swirled in the muck of the Wax Lake delta, covering the mud like kaleidoscopic patches of plastic wrap. Microbes like these work in tandem with marsh plants to draw carbon dioxide from the air and break it down, storing the carbon in the soil.
“People didn’t think about [wetlands] in the way we think today, as a carbon sequestration hot spot,” LSU professor oceanography and wetland studies Kanchan Maiti said.
“If we keep losing wetlands, we’re going to be losing that carbon sink,” said Matt Rota, senior policy director from nonprofit advocacy group Healthy Gulf.
But Louisiana is losing its wetlands, an average of a football field of land lost every 100 minutes, due to subsidence, storm erosion, oil development and sea level rise. The state is home to 40% of U.S. wetlands.
What is the carbon cycle?
Louisiana’s land loss crisis has been widely reported. The state has a multi-billion dollar Coastal Master Plan devoted to addressing the crisis. Now, new research highlighting Louisiana’s wetlands’ role in the carbon cycle argues for more focus on their heightened global value.
When wetlands are destroyed, the carbon they store is released — some ends up in the Gulf, and some is consumed by microbes and gets released into the atmosphere as carbon dioxide, a greenhouse gas contributing to global warming. These microbes also naturally emit methane and nitrous oxide, also greenhouse gases with an even more powerful warming potential than CO2.
With the global carbon cycle thrown out of balance by the burning of fossil fuels, understanding where emissions come from and how carbon is stored is beginning to take center stage.
“This isn’t just our problem … it is also something that I think is pretty easily connected to national and international issues,” said Beaux Jones, CEO of nonprofit research and coastal policy group The Water Institute.
Louisiana in focus
Louisiana’s wetlands are unique; they are stellar carbon storage sites as well as some of the world’s most vulnerable to loss.
“It’s unique, and it’s a natural service for us,” University of Florida geosciences professor Thomas Bianchi said. He has researched carbon sequestration and transport for decades.
Maiti said researchers knew Louisiana’s wetlands were “rich in carbon,” but their importance in the carbon cycle has become more critical as the state grapples with global warming and land loss.
“Our relative sea level is the highest [and] because the wetland is subsiding,” Maiti said, “we’re not getting enough supply of sediment for it to keep up with the sea level rise,” he added.
The state’s relative sea level rise, which takes into account natural subsidence with increased sea levels, is nearly four times the global rate and one of the fastest in the world.
Just how much carbon gets released as CO2 when development and land loss disturb Louisiana’s wetlands is still unclear, Maiti said. But the destruction of the state’s wetlands for oil and gas activity, like the pipeline project near Lake Charles, concerns scientists.
“The moment we start losing this land, we’re going to release that carbon,” Maiti said.
The global carbon budget
Tracking where carbon comes into a system, where it goes out and the speed at which it cycles is important in globally managing how things like excessive CO2 affect the planet, Bianchi said. He and other experts call it a carbon budget, comparing it to the business cycle, where places like marshes act like “banks” for carbon.
Fossil fuels are created from carbon, layered deeper and deeper in the earth over eons. Producing oil, gas and coal takes carbon from underground, burns it and releases it into the air faster than it would have naturally if left underground.
“Now we’re in a situation where, instead of wetlands buying us 1,000 years before this organic carbon goes [and] makes it to the atmosphere, we’re circulating that system, and the carbon is going out the next year,” Maiti said.
Industry interest in carbon capture and sequestration (CCS) technology has grown over the past few years as scientists, industry and lawmakers look for solutions to containing greenhouse gases and balancing the carbon budget. Some see the technology as a vital component in decarbonization as well as a way to garner money and industry jobs, while others see it as a red herring for the climate crisis.
There are 30 CCS projects planned or proposed in Louisiana, and while oil companies and many politicians have embraced them, they have faced pushback from environmental advocates and community members.
“We’re trying to find ways to pull CO2 out of the atmosphere through engineering, but one of the things that is really important is to not lose the systems that are already doing that for us,” Bianchi said.
Balancing the budget
Scientists and advocates alike are calling for increased protection of wetlands because of their natural carbon storage capacity.
Constructed or restored wetlands are other avenues being explored as both ways to increase storm resilience, prevent erosion and store carbon in Louisiana. Research shows new wetlands are extremely efficient at pulling carbon dioxide from the atmosphere and level out to similar levels of carbon storage that naturally formed wetlands do after about 15 years.
Maiti emphasised that while “a constructed wetland, if done properly, and if it is given the time” should work like any natural wetland.
“The beauty of wetlands is they can sequester this carbon for thousands of years,” Maiti said. “I think the key here is the time … anything we are starting from scratch, that will be behind by decades, before it actually reaches the [storage] potential of wetlands we have today.”
Delaney Dryfoos from The Lens contributed to reporting from New Orleans